Exhaust muffler and scavenger apparatus

ABSTRACT

A unitized muffler and scavenger apparatus for use in conjunction with internal combustion engines. The muffler is contained within structure which forms an annular flow passageway through which scavenged gases flow from proximity of the engine to a mixing chamber located downstream within the apparatus. The muffling action is attained by a tube chamber located upstream of a resonator chamber which in turn is located upstream of the before mentioned mixing chamber. A series of radially spaced apart split flow tubes cause the exhaust gases to flow countercurrent as the gases proceed through the apparatus. A tuning element is disposed near the outlet of the apparatus for regulating the noise level as well as the back pressure within the apparatus thus achieving the optimum operating configuration of the apparatus.

United States Patent Overcast 1 Sept. 25, 1973 I EXHAUST MUFFLER AND SCAVENGER APPARATUS Sr.. Houston. all ofTex.

122i Filed: .Ian. 7, 1971 {21] Appl. No.: 216,]58

I,l39.l57 2/!957 France [Bl/64 A Primary Examiner-Richard l3. Wilkinson Assistant Examiner-V. Miska Attorney-Marcus L. Bates [57] ABSTRACT A unitized muffler and scavenger apparatus for use in conjunction with internal combustion engines. The muffler is contained within structure which forms an annular flow passageway through which scavenged gases flow from proximity of the engine to a mixing chamber located downstream within the apparatus. The mufl'ling action is attained by a tube chamber located upstream of a resonator chamber which in turn is located upstream of the before mentioned miltlllg chamber. A series of radially spaced apart split flow tubes cause the exhaust gases to Flow countereurrent as the gases proceed through the apparatus.

A tuning element is disposed near the outlet of the apparatus for regulating the noise level as well as the back pressure within the apparatus thus achieving the optimum operating configuration of the apparatus.

4 Claims, 9 Drawing Figures BACKGROUND OF THE INVENTION Recent legislative emphasis upon air pollution and noise abatement has renewed interest in the disposal of the combustion products as well as the noise from heavy industial internal combustion engines.

lt is desirable to be able to reduce the noise level associated with heavy industrial internal combustion engines to a value which can be tolerated physically as well as physiologically. It is also desirable to remove gaseous products from proximity of the engine so as to lower the probability of explosions or the ingestion of harmful gases by humans. It would be desirable to incorporate these two desirable attributes into a single apparatus wherein the apparatus is compact in size. cffieient in operation. and low in cost.

lt is furthermore desirable that such a system have means associated therewith for transferring heat from the hot gases into the scavenged gases so as to protect the exhaust system from stresses and strains associated with temperature differentials throughout the structure thereof,

SUMMARY OF THE INVENTION This invention comprehends a scavenger and muffler apparatus for internal combustion engines which incltitlcs an elongated inlet pipe about which there is disposed a plurality ofsplit flow tubes. The flow tubes and the pipe have a free depending end portion which is dispo ed in overlapping relationship within a tube chamher with the tubes being flow connected to a resonator chamber which in turn is flow connected to a mixing chamber. A housing encloses the tube chamber and reuinator chamber and forms an annular flow passageway thcrcttbout, The annular passageway has an inlet dis osed adjacent to the inlet tube, and an outlet which terminates in the form of an aspirator. A tuning elemcnt is disposed downstream of the mixing chamber for adjusting the muffler action as well as controlling the pressure drop thcreacross.

Exhaust gases flow through the inlet tube into the tube chamber where it reverses direction and flows countcrcurrent to the gases contained within the tube, whereu on the flow of the gases split and enter the split flow tubes and again reverse direction and flow through the tubes into the resonator chamber. The gases emerging from the resonator chamber induce flow through the annular passageway so that scavenged gases along with the exhaust gases flow into the mixing chamber and then exit around the tuning element.

A primary object of this invention is to provide impro er'ncnts in exhaust muffler and scavenging systems for internal combustion engines.

Another object of the invention is to provide means tv which a mass How of exhaust gases can be utilized to scavenge the atmosphere in proximity of an internal combustion engine.

A further object of this invention is to disclose and rovide a combination muffler and scavenger which redates the noise level of an internal combustion engine to a tolerable level while at the same time scavenging the atmosphere in proximity of the engine.

A still further object of this invention is to provide an im roved unitired muffler and scavenger apparatus which is reliable and efficient in operation, rugged in design, enjoys a long life. and which is low in production costs.

These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.

The above objects are attained in accordance with the present invention by the provision ofa combination of elements which are fabricated in a manner substantially as described in the above abstract and summary.

BRIEF DESCRlPTlON OF THE DRAWlNGS FIG. 1 sets forth a side elevational part crosssectional view of one embodiment of the instant invention. with some parts thereofbeing broken away therefrom so as to disclose the interior thereof. and with other structure being schematically illustrated in conjunction with the invention.

FIG. 2 is a longitudinal cross-sectional representation of apparatus made in accordance with the present invention',

H65. 3, 4, S. 6, 7. and 8. respectively, are crossscctional views taken along lines 3-3; 4-4; 5-5; 6-6; 7-7; and 8-8. respectively. of HO. 2; and

FIG. 9 is a diagrammatical representation of the apparatus disclosed in the foregoing figures which sets forth the principal ofoperation ofthc instant invention.

DETAILED DESCRIPTION OF THE lNVENTlON An internal combustion engine is broadly indicated in H0. l by the arrow at numeral It). The engine is supported by a base It which sets on the Door I2 of a building having a vertical side wall l3. Port 14 is formed within the wall. Spaced apart abutting flanges at l5 and I6 are bolted together in the usual manner with the elbow I? being disposed therebetwcen so that the present invention l8 can be conveniently placed relative to the wall with the outlet [9 thereofcittending through the before mentioned port.

Still looking at FIG. I, but now in conjunction with the remaining figures. the scavenger and muffler apparatus is seen to be comprised of an outermost circumfercntially extending scavenger housing 20 which is concentrically aligned with an innermost pipe 2 l hereinafter referred to as "an inlet pipe." Cylindrical member 22 is axially aligned with and spaced apart from the inlet pipe, and connected to the cylindrical member 23 by means of the illustrated end wall. Cylindrical memhers 23 and 24 therefore cooperate with the remaining structure of the apparatus so as to form an annular passageway 25 having an inlet at 26 through which scavenged gases can flow.

A plurality ofelongated longitudinally extending split flow tubes 27 are radially disposed about and arranged parallel to the before mentioned inlet pipe. The inlet pipe has a terminal end portion 28 in the form of an outlet which is in flow communication with one end of a tube chamber 29.

A rear baffle 30 has a circumfcrentially extending outermost edge portion which is attached to the muffler or silencer housing. The baffle is apcrtured so as to enable the marginal end portion 31 of each of the split flow tubes to be received therein. The tubes preferably are rigidly affixed into position by welding or the like. A forward baffle plate 30' is attached to the exterior surface of the inlet pipe and forms the terminal end of the tube chamber and the silencer housing.

The downstream end portions of the concentrically arranged housings are provided with axially aligned spaced apart flanges 33 and 34. Elements 30, 33, and 24 cooperate together to enable the formation ofa resonator chamber 35. The open terminal end 36 of the reduced portion ofthe chamber forms an outlet which is disposed adjacent to and spaced apart from the interior surface of element 24' to form an aspirator for inducing flow into the scavenged gases contained within the annular passageway.

A tuning element 37 is comprised of a conical member 38 which is supported by a movable band 39. The band is slidably received within the rear reduced portion 24' of the scavenger housing. Numeral 40 indicates one of a plurality of radially spaced apart hangers which maintain the cone affixed to the band.

OPERATION The operation of the apparatus will be described in conjunction with the schematical representation of FIG. 9.

The flange I6 is adapted to he directly or indirectly affixed to the exhaust manifold of any internal combustion engine, so that exhaust gases flow through the inlet pipe and into the tube chamber of the apparatus. The presence of the rear baffle causes the flow of gases to reverse direction l80 and flow in a countercurrent direction back towards the forward baffle. The countercurrent How of gases transfers heat into the silencer housing as the gases again reverse direction 180 and flow through the radially disposed split flow tubes. The gases Flow from outlet 3! into the resonator chamber and through outlet 36 into the mixing chamber 4!. As

the exhaust gases flow into the mixing chamber. part of its energy is expended in forcing gases to flow through the annular passageway. The scavenged gases flow into the inlet 26, through the annular passageway 25. 25'. and thence into the mixing chamber.

The tuning element 38 can be moved toward and away from the resonator chamber so as to tune the muffler and at the same time control the back pressure within the system.

While not specifically shown in the drawings, the inlet pipe can be affixed to the scavenger air inlet by means of radially spaced apart tubular members so as to maintain the two members properly aligned relative to one another. The silencer housing can be affixed to the scavenger housing in a similar manner. The split flow tubes can likewise be affixed to the inlet pipe and the silencer housing so as to maintain the tubes parallel to one another, to the inlet pipe. and to the scavenger housing.

By adjusting the flow of scavenger air through the apparatus. the condensation of water vapor is avoided, thereby eliminating a major source of corrosion within the apparatus. For example. excess cooling of the exhaust gases can result in the condensation of water of combustion contained within the exhaust gases. Control of the rate of flow of the scavenged air through the annulus can be used to advantage to maintain the temperature level of the mixed gases above the eondcnsa tion temperature of water.

Where deemed desirable, a scavenger air flow control means can be affixed at the inlet end 26 of the annulus The flow control means preferably is in the form of a circumferentially extending cylindrical skirt member, slidably received upon member 22, and having apertures therein which are aligned with similar apertures formed in member 22, so as to enable alignment and misalignment of the apertures to control the rate of flow of air through the annular passageway.

I claim:

1. Exhaust silencer and scavenger system for an inter nal combustion engine comprising:

an inlet pipe having an inlet end and an outlet end.

said inlet end adapted to be connected to an exhaust manifold of an internal combustion engine;

a silencer housing concentrically arranged about the longitudinally extending outlet portion of said inlet pipe, a forward and a rear apertured baffle plate; radially spaced apart split flow tubes having an inlet end and an outlet end with the outlet end portion being received through said rear apertured baffle plate.

said forward baffle plate being affixed to and defining a forward end portion of said silencer housing; said inlet pipe being received through said forward baffle plate;

said rear baffle plate being spaced apart from the opposed terminal ends of said silencer housing and from the outlet end ofsaid inlet pipe to form a resonator chamber and a tube chamber, with said tubes flow communicating said tube chamber and said resonator chamber;

said resonator chamber terminating in an outlet pas sageway which is in the form of an elongated reduced diameter portion spaced from said rear haffle plate, said outlet passageway being separated from said split flow tubes by most of said resonator chamber so that gases can flow from the split tubes into the outlet passageway without reversing the direction of How; scavenger housing having an inlet end and an outlet end; said scavenger housing being concentrically arranged externally of said silencer housing and en closing at least part of the longitudinally extending length of said inlet tube, and forming an annular flow passageway about said silencer housing through which scavenged air can flow;

said silencer housing terminating within said scavea gcr housing to form a mixing chamber within which exhaust gases and scavenged air is mixed; and means forming a tuning element within a marginal end portion of said scavenger housing.

2. The apparatus of claim 1, wherein said scavenger housing reduces in cross-sectional area between said forward baflie and said inlet end of said inlet pipe to thereby reduce the outermost dimension of said annular flow passageway. and to form a scavenger air inlet in close proximity of the inlet of said inlet tube.

3. The apparatus of claim l wherein said tuning element is centrally located downstream of said mixing chamber, means by which said tuning element can be moved towards and away from said silencer outlet to thereby vary the size of said mixing chamber.

4. A scavenger and muffler apparatus for internal combustion engines comprising:

an elongated inlet pipe adapted to be flow connected to an internal combustion engine;

a plurality of split flow tubes; means forming a tube chamber, a resonator chamber. and a mixing chamher; said split fiow tubes being radially disposed about and parallel to said inlet tube, said inlet tube having part of its length disposed within said tube chamber with the outlet thereof flow connected to said tube chamber. said split flow tubes having part of the length thereof disposed within said tube chamber. with an inlet thereof being located within said tube chamber. and an outlet thereof being located in said resonator chamber;

said resonator chamber having a reduced diameter portion which forms an outlet flow passageway from said resonator chamber into said mixing chamber; said outlet flow passageway being spaced from said split flow tubes with most of said resonator being interposed therebetween so that gases tion of said mixing chamber.

O l 0 0 l 

1. Exhaust silencer and scavenger system for an internal combustion engine comprising: an inlet pipe having an inlet end and an outlet end, said inlet end adapted to be connected to an exhaust manifold of an internal combustion engine; a silencer housing concentrically arranged about the longitudinally extending outlet portion of said inlet pipe; a forward and a rear apertured baffle plate; radially spaced apart split flow tubes havIng an inlet end and an outlet end with the outlet end portion being received through said rear apertured baffle plate; said forward baffle plate being affixed to and defining a forward end portion of said silencer housing; said inlet pipe being received through said forward baffle plate; said rear baffle plate being spaced apart from the opposed terminal ends of said silencer housing and from the outlet end of said inlet pipe to form a resonator chamber and a tube chamber, with said tubes flow communicating said tube chamber and said resonator chamber; said resonator chamber terminating in an outlet passageway which is in the form of an elongated reduced diameter portion spaced from said rear baffle plate, said outlet passageway being separated from said split flow tubes by most of said resonator chamber so that gases can flow from the split tubes into the outlet passageway without reversing the direction of flow; a scavenger housing having an inlet end and an outlet end; said scavenger housing being concentrically arranged externally of said silencer housing and enclosing at least part of the longitudinally extending length of said inlet tube, and forming an annular flow passageway about said silencer housing through which scavenged air can flow; said silencer housing terminating within said scavenger housing to form a mixing chamber within which exhaust gases and scavenged air is mixed; and means forming a tuning element within a marginal end portion of said scavenger housing.
 2. The apparatus of claim 1, wherein said scavenger housing reduces in cross-sectional area between said forward baffle and said inlet end of said inlet pipe to thereby reduce the outermost dimension of said annular flow passageway, and to form a scavenger air inlet in close proximity of the inlet of said inlet tube.
 3. The apparatus of claim 1 wherein said tuning element is centrally located downstream of said mixing chamber, means by which said tuning element can be moved towards and away from said silencer outlet to thereby vary the size of said mixing chamber.
 4. A scavenger and muffler apparatus for internal combustion engines comprising: an elongated inlet pipe adapted to be flow connected to an internal combustion engine; a plurality of split flow tubes; means forming a tube chamber, a resonator chamber, and a mixing chamber; said split flow tubes being radially disposed about and parallel to said inlet tube, said inlet tube having part of its length disposed within said tube chamber with the outlet thereof flow connected to said tube chamber, said split flow tubes having part of the length thereof disposed within said tube chamber, with an inlet thereof being located within said tube chamber, and an outlet thereof being located in said resonator chamber; said resonator chamber having a reduced diameter portion which forms an outlet flow passageway from said resonator chamber into said mixing chamber; said outlet flow passageway being spaced from said split flow tubes with most of said resonator being interposed therebetween so that gases may flow from said split flow tubes directly into said outlet flow passageway without reversing the direction of flow; means forming an annular air chamber about said tube chamber and said resonator chamber, with said air chamber terminating at and being flow connected to said mixing chamber; aspirator means for enabling flow of exhaust gases through said resonator chamber to induce the flow of air through said annular air chamber; and further including means forming a tuning element which is located within a marginal end portion of said mixing chamber. 